In a rolling mill in which hot rolled product is formed into rings by a laying head and the rings are transported in an overlapping pattern to a reforming station where the rings are gathered into coils, a method of increasing the time gap between billet lengths of product delivered to the reforming station by advancing the rings of a front end of one billet along said conveyor at a one speed while advancing the rings of a tail end of a preceding billet at another speed greater than said one speed.